Re: Connector - how to start?

Matt Helsley
2006-04-15T03:16:38Z

On Fri, 2006-04-14 at 19:26 -0700, Randy.Dunlap wrote:
> On Sat, 15 Apr 2006 03:09:05 +0200 Libor Vanek wrote:
>
> > Hi,
> > I'd like to start writing some small module using connector to send
> > messages to/from user-space. Unfortunately I'm absolutely not familiar
> > with netlink/connector API usage and I couldn't find any usefull
> > documentation (yes, I read Documentation/connector/ and tried Google).
> >
> > So here's things which are not clear to me:
> > - the Documentation/connector containts only kernel-space example -
> > don't anybody have also "user-space client example"?
> > - how do I ACK message sent to/from user-space?
> > - in case of multiple clients listening how do I send message just to
> > (random) one (simple load balancing) or to all of them? (broadcasting)
> > - is there some "easy" way how to send longer messages then
> > CONNECTOR_MAX_MSG_SIZE?
>
> There was a connector userspace example posted to lkml on
> 2005-SEP-28:
>
> Subject: [RFC] Process Events Connector (test program)
> From: Matthew Helsley <matthltc@us.ibm.com>
>
>
> It seems like one of the Red Hat guys had some netlink documentation
> and sample programs at people.redhat.com, but I can't find that
> just now.
>
> ---
> ~Randy

Subject:[ANNOUNCE] Test Program for Filesystem Events Reporter
From:
Yi Yang <yang.y.yi@gmail.com>

might demonstrate what you're looking for as well.

I don't believe there is an existing way to send messages longer than
CONNECTOR_MAX_MSG_SIZE. Perhaps you could send multiple messages with
the same sequence number but a different "fragment number" in the
message.

However, if you're sending messages much larger than
CONNECTOR_MAX_MSG_SIZE perhaps the medium of communication is not
appropriate. Have you considered relay files?

Cheers,
-Matt Helsley